|
Section Number
|
Topic
|
Descriptor
|
|
Option H:
Optics (15h)
|
|
H.1 The Nature
of Light (3h)
|
|
Speed of
light
|
|
H.1.1
|
Outline the
electromagnetic nature of light.
|
It is
sufficient for students to know that an oscillating electric
charge produces
sinusoidally varying electric and magnetic fields and that
the energy of
the oscillating charge is propagated by means of the
varying fields.
Students should know that electromagnetic waves are
transverse waves
and can travel in a vacuum.
|
|
H.1.2
|
Describe the different
regions of the electromagnetic spectrum.
|
Students should
know the order of magnitude of the frequencies for
the different
regions, and should also be able to identify a possible
source of the
radiation in each region.
|
|
H.1.3
|
Outline an experiment
that measures the speed of light in a
vacuum.
|
No specific
experiment is required, but Michelson's method involving
a rotating
mirror would be appropriate. Experimental details are
not required.
Students should be aware that the speed of light in vacuum
is now a defined
value in terms of which the metre is
defined.
|
|
Dispersion
|
|
H.1.4
|
Describe the dispersion
of white light by a prism.
|
Students should
know that different colours disperse in order of
decreasing frequencies
and that the colours can combine to produce white
light.
|
|
H.1.5
|
Explain the dispersion of
white light by a prism in terms of the frequency
dependence of refractive
index.
|
No quantitative
discussion is required but students should know that
the refractive
index for glass is smaller for red light than it is for blue
light.
|
|
Lasers
|
|
H.1.6
|
Identify laser light as a
source of monochromatic, coherent
light.
|
Students should
be able to explain monochromatic and
coherent.
|
|
H.1.7
|
Outline a laser
application from technology, industry or
medicine.
|
Possible
examples include: technology
(bar-code scanners, laser discs)
industry (surveying,
welding and machining metals, drilling tiny
holes in metals)
medicine (destroying
tissue in small areas, attaching the retina, corneal
correction, cauterizing
lymph vessels and capillaries).
|
|
H.2 Reflection
at a Plane Surface (2h)
|
|
Nature of
reflection
|
|
H.2.1
|
Distinguish between
reflection at a mirror and diffuse
reflection.
|
|
|
H.2.2
|
Define the terms
normal, incident ray, reflected
ray.
|
Students should
know that the ray is a line that is perpendicular to
the wave fronts.
They should recognize geometric optics as a study in
which the wave
nature of light can be ignored.
|
|
H.2.3
|
State the law of
reflection.
|
|
|
Formation of an
image by reflection
|
|
H.2.4
|
Construct a ray diagram
to determine the formation of an image by
reflection at a plane
surface.
|
|
|
H.2.5
|
Explain the difference
between a real and a virtual
image.
|
|
|
H.2.6
|
Describe the nature of
the image formed by reflection.
|
|
|
H.3 Refraction
at a Plane Interface (3h)
|
|
Snell's law and
refractive index
|
|
H.3.1
|
Define refractive
index.
|
|
|
H.3.2
|
Solve problems involving
Snell's law and refractive index.
|
|
|
Image
formation
|
|
H.3.3
|
Describe the nature of
the image formed by refraction at a plane
surface.
|
|
|
H.3.4
|
Explain why when part of
a stick is immersed in water it appears to be
bent.
|
|
|
H.3.5
|
Explain why the apparent
depth of a body immersed in a liquid is not its
actual depth.
|
|
|
H.3.6
|
Derive the formula
connecting real depth, apparent depth and refractive
index.
|
|
|
H.3.7
|
Solve problems involving
refraction at a plane interface.
|
|
|
Critical
angle
|
|
H.3.8
|
State that, in general,
light will be partially transmitted and partially
reflected at a boundary between
two media.
|
|
|
H.3.9
|
Describe the phenomenon
of total internal reflection.
|
Students should
understand the terms critical ray and critical
angle.
|
|
H.3.10
|
Derive a relationship
between the critical angle and the refractive indices
of the
media.
|
|
|
H.3.11
|
Solve problems involving
total internal reflection.
|
|
|
H.3.12
|
Explain the view as seen
by an underwater observer when looking at the
water-air
interface.
|
|
|
H.3.13
|
Describe the action of
prismatic reflectors.
|
For example,
periscopes or binoculars.
|
|
H.3.14
|
Discuss how a light ray
is transmitted along the length of an optical
fibre.
|
|
|
H.3.15
|
Outline the uses of
optical fibres.
|
It is
sufficient that students know how optical fibres are used in
the transmission
of data and in medicine (endoscopes).
|
|
H.4 Refraction
by Lenses (3h)
|
|
Types of
lenses
|
|
H.4.1
|
Explain qualitatively, in
terms of refraction, the converging and diverging
action of lenses.
|
|
|
H.4.2
|
Identify whether a lens
is converging or diverging.
|
|
|
Image
formation
|
|
|
|
H.4.3
|
Define the terms
principal axis, focal point, focal
length, linear magnification.
|
|
|
H.4.4
|
Construct ray diagrams to
locate images formed by lenses.
|
Students should
appreciate that any other rays incident on the lens from
the object will
also be focused, and that the image will be formed even if
some of the rays
are blocked off.
|
|
H.4.5
|
Determine the nature of
images formed by different types of lenses with
different object-to-lens
separations.
|
|
|
H.4.6
|
Solve problems for a
single lens and a combination of lenses using the
thin lens
equation
|
Problems can be
solved either by scale drawing or calculation. Students
do not need to
know the lensmaker's formula.
|
|
H.5 Optical
Instruments (4h)
|
|
Note: Only single- and
two -lens instruments will be considered .
|
|
The simple
magnifying glass
|
|
H.5.1
|
Define the terms near
point and far point for the unaided
eye.
|
The near point
is also known as the Òleast distance of distinct
visionÓ. For the
normal eye, the far point can be taken to be infinity and
the near point is
conventionally taken as 25 cm. (The optical principles
inside the eye are not
required.)
|
|
H.5.2
|
Define angular
magnification.
|
|
|
H.5.3
|
Derive an expression for
the angular magnification of a simple magnifying
glass when the image is formed at
the near point and at infinity.
|
|
|
The compound
microscope and astronomical telescope
|
|
H.5.4
|
Construct a ray diagram
to determine the position of the final image formed
by a compound microscope used in
normal adjustment.
|
Students should
be familiar with the terms objective lens and
eyepiece lens.
|
|
H.5.5
|
Construct a ray diagram
to explain how the image is formed by an astronomical
telescope.
|
Only the case
for image at infinity is required.
|
|
H.5.6
|
Derive the equation
relating angular magnification and focal lengths of
the lenses in an
astronomical telescope.
|
|
|
H.5.7
|
Solve problems involving
the compound microscope and the astronomical
telescope.
|
Problems can be
solved either by scale ray diagrams or by
calculation.
|
|
Aberrations
|
|
H.5.8
|
Describe the meaning of
spherical aberration and chromatic
aberration.
|
|
|
H.5.9
|
Describe a method to
reduce or eliminate the effect of spherical
aberration.
|
|
|
H.5.10
|
Describe a method to
reduce the effect of chromatic aberration.
|
|
|
Option H:
Extension Material (HL only) (7h)
|
|
H.6 Diffraction
and Interference (5h)
|
|
Note: All diffraction in
this section is taken to be Fraunhofer diffraction,
ie involving plane wave
fronts.
|
|
Diffraction
|
|
H.6.1
|
Draw the diffraction
fringe patterns produced by a single edge, a narrow
slit and a circular
aperture.
|
|
|
H.6.2
|
Explain diffraction
patterns qualitatively.
|
|
|
H.6.3
|
Draw the relative
intensity versus angle plot for the diffraction of light at
a single
slit.
|
|
|
H.6.4
|
Derive the condition for
the position of the minima of the diffraction
pattern.
|
Students should
be aware of the small angle approximation for the
condition and should
also be able to calculate the full width of the
b£f £c
=central maximum in terms of the distance of the slit from
the screen.
|
|
H.6.5
|
Explain the effect that
diffraction has on the intensity distribution of the
fringes produced by double slit
interference.
|
Students should
be able to sketch the intensity distribution for finite
slit widths and
calculate the positions of the interference and diffraction
minima.
|
|
Resolution
|
|
H.6.6
|
Draw a relative intensity
versus angle plot for the diffraction produced by
light from two sources that
passes through a slit, for situations where the
diffraction patterns are well
resolved, just resolved and not resolved.
|
|
|
H.6.7
|
State the Rayleigh
criterion for two sources to be just
resolved.
|
|
|
H.6.8
|
Solve problems involving
the resolution of two sources diffracted by a slit
and by a circular
aperture.
|
The derivation
of is not required. 1.22 b£f
£c =
|
|
Multiple slit
diffraction
|
|
H.6.9
|
Explain the effect on the
double slit intensity distribution of adding further
slits at the same slit
separation.
|
Students should
be able to explain why the principal maxima maintain
the same
separation but become much sharper.
|
|
H.6.10
|
Derive the diffraction
grating formula.
|
|
|
H.6.11
|
Outline how the
diffraction grating is used to investigate spectra
and measure
wavelength.
|
Students should
also be able to explain what happens when white light
is incident on a
diffraction grating.
|
|
H.6.12
|
Solve problems involving
the diffraction grating.
|
Knowledge of
the spectrometer is not required.
|
|
H.7 Thin Film
Interference (2h)
|
|
Parallel
films
|
|
H.7.1
|
State the conditions for
light to undergo either a phase change of ¹, or
no phase change, on
reflection from an interface.
|
|
|
H.7.2
|
Describe how a source of
light gives rise to an interference pattern when the
light is reflected by both
surfaces of a parallel film.
|
|
|
H.7.3
|
Derive the conditions for
constructive and destructive interference.
|
|
|
H.7.4
|
Solve problems involving
parallel films.
|
|
|
H.7.5
|
Explain the formation of
coloured fringes when white light is reflected from
thin films, such as oil films and
bubbles.
|
|
|
Wedge
films
|
|
H.7.6
|
Explain the production of
interference fringes by a thin air wedge.
|
|
|
H.7.7
|
Describe how wedge
fringes can be used to measure very small
separations.
|
|